|Publication number||US7229321 B2|
|Application number||US 11/124,919|
|Publication date||Jun 12, 2007|
|Filing date||May 3, 2005|
|Priority date||May 3, 2004|
|Also published as||CN1694308A, CN100365871C, DE102004021529A1, DE102004021529B4, EP1594193A1, EP1594193B1, US20050245144|
|Publication number||11124919, 124919, US 7229321 B2, US 7229321B2, US-B2-7229321, US7229321 B2, US7229321B2|
|Original Assignee||Lumberg Connect Gmbh & Co. Kg|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (12), Referenced by (2), Classifications (7), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The present invention relates to an electrical contact. More particularly this invention concerns a gripper contact for engagement with an edge of a circuit board, contact blade, or the like.
In the accompanying drawing:
It is standard practice as shown in
The arms 12′ and 13′ are formed with contact bumps 16′ and 17′ having surfaces 16 a′ and 17 a′ that are offset in an insertion direction 18′ lying on a central plane of the contact 11′ by a short distance 19′ so as to form two differently angled faces 26′ and 27′. The circuit board 20 has a dielectric rigid core plate 21′ with conductive traces 22′ and 23′ on its opposite faces. At its edge inserted into the contact 11′ it has two sharp edges 24′ and 25′. In order to prevent these edges 24′ and 25′ from digging too deeply into the normally soft metal—copper or gold—coating the faces 16 a′ and 17 a′, the edges are beveled off at 31′.
The offset 19′ is intended to make it easier to fit the board 20′ into the contact 11′. Normally it will engage the one arm 11′ and pry it out, then hit the other arm 13′, so that they will not both engage it at the same time. The face 26 extends at an angle W′ of about 30° to the direction 18′. Combined with the bevel 31′, the edge 24′ meets the face 26′ at a fairly flat angle, in theory minimizing any tendency of it to dig in. The use of such a flat angle limits the throat or width of the opening defined between the arms 12′ and 13′, but is necessary to prevent damage to the contact assembly 10′.
Such a contact assembly 10′, used for example to fit to the edge of the printed-circuit connector of a liquid-crystal display, can be made relatively compact and, by virtue of the gripping action, maintains a good electrical connection with the part that if fitted in it. When, however, it is intended for an application, for instance in a cell phone, where it is subject to frequent plugging-in and unplugging of some other piece of equipment, it can quickly wear out. Even with the bevels 31′, the edges 24′ and 25′ cut into the surfaces 16 a′ and 17 a′, with the result that the conductive coating is damaged and the electrical connection becomes intermittent or develops significant resistance.
It is known, for example from German 2,809,830, U.S. Pat. No. 3,858,957, and U.S. Pat. No. 3,262,082, to shape the outer ends of the contacts to guide the part into the slot formed between the contact arms. In these systems, the outer ends are spaced somewhat more widely than the actual contact bumps that eventually serve for conducting electricity to and/or from the part fitted to the contact, so that they are in fact exposed to damage as explained above and offered no significant protection by the outer formations.
It is therefore an object of the present invention to provide an improved gripper contact.
Another object is the provision of such an improved gripper contact that overcomes the above-given disadvantages, in particular that can be counted on to have a long service life, even with repeated use.
An electrical contact has according to the invention a pair of arms extending generally parallel to and spaced apart transversely of an insertion direction, each having an outer end and an inner end, and defining a slot open outward in the insertion direction. Each arm outer end has an end face extending at an acute angle to the direction. The end faces diverge outward from each other in the direction, and a bight interconnects the arm inner ends. The arms are limitedly elastically deformable for elastic displacement of the arm outer ends perpendicular to the direction so that a part pressed in the insertion direction against the end faces elastically spreads the arm outer ends. An inner contact bump projects on each arm between the respective end face and the bight transversely of the direction into the slot. The inner bumps are spaced apart transverse to the direction by a predetermined inner spacing. An outer bump projects on each arm from between the respective inner bump and the respective end face transversely of the direction into the slot. The outer bumps are spaced apart transverse to the direction by a predetermined outer spacing equal at most to the inner spacing.
Thus with this system, as a part is pushed into the slot, it will first engage the end faces and spread the arms until the part has slipped between the outer bumps. Further inward movement will engage it between the inner bumps, but by the time the part actually enters into contact with the inner bumps they will be spread to a spacing equal almost to that of the outer bumps. According to the invention in a relaxed condition of the contact the inner and outer spacings are generally the same. Since the arms are connected together by the bight at their inner ends, the spacing between the inner bumps will be slightly less than that of the outer bumps, even if they start out at identical spacing, when the outer ends are levered apart. This system is particularly effective in arrangements where the part being inserted into the contact moves in a straight line, not where it can be tipped from one side to the other and worked into place.
The acute angle formed by the outer end faces to the direction is between 40° and 50°. This does, admittedly, make it possible for sharp edges on the inserted part to scrape on these faces, but since they are not used for electrical connection this is not serious. On the other hand, the wide angle provides a big mouth for the slot, making it easy to insert the part thereinto.
The inner bumps each have a flat outer flank forming an angle of between 15° and 30° to the direction. The outer flanks diverge outward in the direction. This extremely small angle ensures that the part, as it slides onto the inner bumps, will not be likely to dig into the metal coating on these bumps.
The bumps are unitarily formed with the respective arms. The arms can be solid metal or plastic-coated metal, as in a molded interconnect device system.
In addition inner bumps are spaced directly across from each other perpendicular to the direction while one of the outer bumps is spaced in the direction outward of the other of the outer bumps. Thus the part will engage the one outer bump, and then shift laterally into position as it bends out the one arm, making the action of insertion into the slot fairly gentle.
As seen in
The contact 11 is formed outward of the bumps 16 and 17 on the arms 12 and 13 with guide bumps 29 and 30 offset in the direction 18 by a spacing 28 and having faces 29 a and 30 a lying at the inner ends of respective planar mouth faces 26 and 27. Perpendicular to the insertion direction 18, the outer bumps 29 and 30 are spaced apart by an outer distance or spacing So. The face 26 extends at an angle W of about 48° to the plane P and direction 18, and the face 27 at a slightly smaller angle. As a result at their outer ends the arms 12 and 13 form a fairly wide mouth. The spacing So between the outer bumps 29 and 30 is at most equal to the spacing Si between the inner bumps 16 and 17, and here is in fact equal thereto in the relaxed
As shown in
By the time as shown in
The contact 11 according to the invention could also be made as a flat-spring contact, an MID contact, or of other similar construction. Similarly the part 20 could be a printed-circuit board as shown, a blade contact, an MID contact, or the like.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US3040291 *||May 4, 1961||Jun 19, 1962||Methode Electronics Inc||Electric connector socket|
|US3262082||Oct 10, 1963||Jul 19, 1966||Schjeldahl Co G T||Electrical connector for printed circuit board|
|US3631381 *||Apr 2, 1970||Dec 28, 1971||Ind Electronic Hardware Corp||Multiple electrical connector|
|US3858957||Aug 27, 1973||Jan 7, 1975||Amp Inc||Electrical connecting members requiring lower insertion and retraction forces and providing for low contact wear|
|US5082459 *||Aug 23, 1990||Jan 21, 1992||Amp Incorporated||Dual readout simm socket|
|US6254435 *||Jun 1, 1999||Jul 3, 2001||Molex Incorporated||Edge card connector for a printed circuit board|
|US6652372 *||Jun 28, 2001||Nov 25, 2003||Valeo Klimasysteme Gmbh||Airflap|
|US6764345 *||May 27, 2003||Jul 20, 2004||Tyco Electronics Corporation||Electrical card edge connector with dual shorting contacts|
|CH424905A||Title not available|
|DE1046137B||Apr 30, 1957||Dec 11, 1958||Kupfer Asbest Co||Elektrische Kontaktvorrichtung fuer gedruckte Schaltungen|
|DE2809830A1||Mar 7, 1978||Sep 14, 1978||Bunker Ramo||Elektrisches anschlussteil|
|DE3023614A1||Jun 24, 1980||Jan 14, 1982||Hans Dipl Ing Rilling||Contact strip for LCD - has contact elements with retaining forms that are inset into plastic block|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US20110136387 *||Jun 9, 2009||Jun 9, 2011||Molex Incorporated||Card edge connector|
|US20140057494 *||Aug 22, 2013||Feb 27, 2014||Amphenol Corporation||High-frequency electrical connector|
|International Classification||H01R13/115, H01R13/11, H01R24/00|
|Cooperative Classification||H01R12/721, H01R13/112|
|Jul 14, 2005||AS||Assignment|
Owner name: LUMBERG CONNECT GMBH & CO. KG, GERMANY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEGEL, JORG;REEL/FRAME:016780/0634
Effective date: 20050614
|Dec 13, 2010||FPAY||Fee payment|
Year of fee payment: 4
|Apr 11, 2013||AS||Assignment|
Owner name: LUMBERG CONNECT GMBH, GERMANY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:LUMBERG CONNECT GMBH & CO.KG;REEL/FRAME:030211/0455
Effective date: 20061201
|Dec 8, 2014||FPAY||Fee payment|
Year of fee payment: 8